Apparatus for extracting sanding dust from rotary sanders

ABSTRACT

An apparatus for extracting sanding dust from rotary sanders includes a suction hood disposed on a suction pipe and enclosing a drive group and a flexible or moveable grinding head which faces the surface to be machined. A sealing profile leads around the entire periphery of the suction hood and at least one secondary air valve disposed in the suction pipe is configured in such a way that an opening in the suction pipe is regulated by the secondary air valve. The suction hood has at least one auxiliary air hole which penetrates the suction hood from the surface to the interior of the suction hood.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority, under 35 U.S.C. §119, of German Application DE 20 2015 000 409.1, filed Jan. 22, 2014; the prior application is herewith incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The invention relates to an apparatus for extracting sanding dust from rotary sanders, especially dry wall sanders.

The invention pertains to a suction apparatus for sanders with a rotating abrasive, which is at least partially enclosed by a suction hood, known in the trade, in which the suction hood has a solid peripheral rim for support and an elastic spring element, which allows flexible movement of the suction hood basically parallel to the axis of rotation of the rotating abrasive relative to the sander.

Such a device is described, for example, in German Application DE 10 2008 059 585. The sliding behavior of a sander equipped with that extraction attachment on the work surface should be significantly improved due to the suction hood having a solid peripheral rim for support.

German Application DE 69 33 862 also discloses a device for extracting dust from orbital sanders, in which a cuff made of an elastic plastic material encloses the orbital sander with a side connector for the attachment of a vacuum cleaner hose.

German Application DE 20 2005 011 659 describes a sander which includes a head part, a handle which is swivel-mounted on the head part, at least one grinding disk pivot-mounted on the head part, a drive unit for the grinding disk, a hood which covers at least one grinding disk and encloses it with its rim, and a connector on the hood for attaching a vacuum cleaner.

A replaceable sliding ring is attached at the edge of the hood. At least one grinding disk and the sliding ring are adjustable relative to one another so that the front edge of the sliding ring and the front face of the grinding disk are aligned.

In that way, when at least one grinding disk is moved over the surface of a wall or a ceiling during sanding, the sliding ring slides on that surface, thereby virtually sealing off the gap between the hood and the surface being machined to the suction air flow.

Then the vacuum cleaner can generate a negative pressure under the hood sufficient to hold the head part to the wall. The required negative pressure can definitely be generated by a standard vacuum cleaner, because the hood covers the grinding disk and is therefore considerable in size, and thus has a determining influence not only on the attainable negative pressure, but also on the attainable holding force.

In order for the dust to be extracted, air has to be able to be sucked under the hood. Since the sliding ring slides on a rough surface, e.g. on plaster, and the slide ring is subject to wear, which can roughen it and make it a bit uneven, air can still be sucked under the hood through the gap left between the sliding ring and the machined surface despite the sliding of the sliding ring on the machined surface.

The disadvantage of all known technical devices for this purpose is that the housing is drawn against the wall or the ceiling, that is to say, to the grinding surface, thus making handling difficult.

SUMMARY OF THE INVENTION

It is accordingly an object of the invention to provide an apparatus for extracting sanding dust from rotary sanders, which overcomes the hereinafore-mentioned disadvantages of the heretofore-known apparatuses of this general type to the point that it can be ensured that as soon as the sanding dust and swarf are created, they can be suctioned up by a vacuum cleaner as thoroughly as possible, but without having the sander stick to the wall or ceiling.

With the foregoing and other objects in view there is provided, in accordance with the invention, an apparatus for extracting sanding dust from rotary sanders. The apparatus comprises a flexible grinding head facing a surface to be machined, a drive group and a suction pipe. A suction hood is disposed on the suction pipe and encloses the drive group and the flexible grinding head. The suction hood has an outer periphery and a sealing profile leading entirely around the outer periphery of the suction hood. The suction hood has an outer surface, an interior and at least one auxiliary air hole penetrating the suction hood from the outer surface to the interior of the suction hood. At least one secondary air valve is disposed in the suction pipe and configured to regulate an opening in the suction pipe.

In accordance with another feature of the invention, the sealing profile is formed of brushes.

In accordance with a further feature of the invention, the sealing profile is formed as a silicone lip.

In accordance with a concomitant feature of the invention, the at least one auxiliary air hole is a plurality of auxiliary air holes distributed in a uniform circular ring on the suction hood.

Other features which are considered as characteristic for the invention are set forth in the appended claims.

Although the invention is illustrated and described herein as embodied in an apparatus for extracting sanding dust from rotary sanders, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The FIGURE of the drawing is a perspective view of an embodiment of the apparatus for extracting sanding dust from rotary sanders according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now in detail to the single FIGURE of the drawing, there is seen an apparatus according to the invention for extracting sanding dust from rotary sanders, which is formed of a drive group disposed on a suction pipe 6 and a flexible or movable grinding head or tool 3.

The drive group and the flexible grinding head 3 are enclosed by a suction hood 1, which faces the surface to be machined, and which has a sealing profile leading around the entire circumference of the suction hood.

The grinding dust is transported from the grinding head 3 towards the dust extraction apparatus through a suction tune 4 and the suction pipe 6, which serves as a support member and guide rod for the drive group and the flexible grinding head.

Typically, a standard vacuum cleaner is used as a suction device.

The flow of air generated by the suction apparatus and drawn through the suction tube 4 and the suction pipe 6, is adjusted by using a secondary air valve 5.

This secondary air valve 5 is disposed in the exhaust pipe 6 and provided in such a way that this same secondary air valve 5 can open or close an opening in the suction pipe 6.

The suction hood 1 of the grinding head is equipped with a sealing profile 2, which rests on the surface to be machined.

The sealing profile 2 is engineered in such a way that the escape of grinding dust in the area of the grinding head 3 is prevented during machining, but at the same time, the smooth gliding of the grinding head over the machined surface is achieved.

It has proven advantageous in this case, to provide the sealing profile 2 as a silicone lip.

In order to prevent the suction hood 1 from being sucked down too hard on the surface being machined when the secondary air valve 5 is closed, the suction hood 1 is provided with auxiliary air holes 7.

These auxiliary air holes 7 are preferentially disposed so that they penetrate the top or outer surface of the suction hood 1 into the interior of the suction hood 1.

It has proven advantageous to distribute these auxiliary air holes 7 in a circular ring on the exhaust hood 1 as seen in a section A of the drawing.

This ensures a minimum airflow that, on one hand, ensures an adequate flow of air for suctioning, and on the other hand, reduces the suctioning force of the suction hood 1 against the surface to be machined to the extent that the sander can be moved without a problem over the surface.

Thus, the secondary air valve 5 has the following functions:

Adjustment of the suction force of the suction hood 1, actually for the entire grinding head 3, and thus a significant relief for the operator, since the weight of the machine is reduced. This is particularly favorable, for example, when working overhead.

The operator only needs to exert a fraction of the contact pressure for the sanding process, since the suctioning always pulls the grinding head towards the surface.

The airflow situation can be easily adapted to different suctioning devices according to the parameters of the vacuum cleaner being used by using the air valve 5.

Through the use of the apparatus according to the invention, it is now possible to use vacuum cleaners which do not have their own suction power control, so that further cost savings are achieved. 

1. An apparatus for extracting sanding dust from rotary sanders, the apparatus comprising: a flexible grinding head facing a surface to be machined; a drive group; a suction pipe; a suction hood disposed on said suction pipe and enclosing said drive group and said flexible grinding head, said suction hood having an outer periphery and a sealing profile leading entirely around said outer periphery of said suction hood, said suction hood having an outer surface, an interior and at least one auxiliary air hole penetrating said suction hood from said outer surface to said interior of said suction hood; and at least one secondary air valve disposed in said suction pipe and configured to regulate an opening in said suction pipe.
 2. The apparatus according to claim 1, wherein said sealing profile is formed of brushes.
 3. The apparatus according to claim 1, wherein said sealing profile is formed as a silicone lip.
 4. The apparatus according to claim 1, wherein said at least one auxiliary air hole is a plurality of auxiliary air holes distributed in a uniform circular ring on said suction hood. 